include/fcntl.h

   1 /* Copyright (C) 1991,1992,1994-2001,2003,2004,2005,2006,2007, 2009
   2         Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 /*
  20  *      POSIX Standard: 6.5 File Control Operations     <fcntl.h>
  21  */
  22
  23 #ifndef _FCNTL_H
  24 #define _FCNTL_H        1
  25
  26 #include <features.h>
  27
  28 /* This must be early so <bits/fcntl.h> can define types winningly.  */
  29 __BEGIN_DECLS
  30
  31 /* Get the definitions of O_*, F_*, FD_*: all the
  32    numbers and flag bits for `open', `fcntl', et al.  */
  33 #include <bits/fcntl.h>
  34
  35 /* For XPG all symbols from <sys/stat.h> should also be available.  */
  36 #ifdef __USE_XOPEN
  37 # include <sys/stat.h>
  38 #endif
  39
  40 #ifdef  __USE_MISC
  41 # ifndef R_OK                   /* Verbatim from <unistd.h>.  Ugh.  */
  42 /* Values for the second argument to access.
  43    These may be OR'd together.  */
  44 #  define R_OK  4               /* Test for read permission.  */
  45 #  define W_OK  2               /* Test for write permission.  */
  46 #  define X_OK  1               /* Test for execute permission.  */
  47 #  define F_OK  0               /* Test for existence.  */
  48 # endif
  49 #endif /* Use misc.  */
  50
  51 /* XPG wants the following symbols.  */
  52 #ifdef __USE_XOPEN              /* <stdio.h> has the same definitions.  */
  53 # define SEEK_SET       0       /* Seek from beginning of file.  */
  54 # define SEEK_CUR       1       /* Seek from current position.  */
  55 # define SEEK_END       2       /* Seek from end of file.  */
  56 #endif  /* XPG */
  57
  58 #ifdef __USE_ATFILE
  59 # define AT_FDCWD               -100    /* Special value used to indicate
  60                                            the *at functions should use the
  61                                            current working directory. */
  62 # define AT_SYMLINK_NOFOLLOW    0x100   /* Do not follow symbolic links.  */
  63 # define AT_REMOVEDIR           0x200   /* Remove directory instead of
  64                                            unlinking file.  */
  65 # define AT_SYMLINK_FOLLOW      0x400   /* Follow symbolic links.  */
  66 # ifdef __USE_GNU
  67 #  define AT_NO_AUTOMOUNT       0x800   /* Suppress terminal automount
  68                                            traversal.  */
  69 #  define AT_EMPTY_PATH         0x1000  /* Allow empty relative pathname.  */
  70 #  define AT_STATX_SYNC_TYPE    0x6000
  71 #  define AT_STATX_SYNC_AS_STAT 0x0000
  72 #  define AT_STATX_FORCE_SYNC   0x2000
  73 #  define AT_STATX_DONT_SYNC    0x4000
  74 #  define AT_RECURSIVE          0x8000  /* Apply to the entire subtree.  */
  75 # endif
  76 # define AT_EACCESS             0x200   /* Test access permitted for
  77                                            effective IDs, not real IDs.  */
  78 #endif
  79
  80 /* Do the file control operation described by CMD on FD.
  81    The remaining arguments are interpreted depending on CMD.
  82
  83    This function is a cancellation point and therefore not marked with
  84    __THROW.  */
  85 #if !defined(__USE_FILE_OFFSET64) || defined(__LP64__)
  86 extern int fcntl (int __fd, int __cmd, ...);
  87 # ifdef _LIBC
  88 extern int __fcntl_nocancel(int, int, long) attribute_hidden;
  89 libc_hidden_proto(fcntl)
  90 # endif
  91 #else
  92 # ifdef __REDIRECT
  93 extern int __REDIRECT (fcntl, (int __fd, int __cmd, ...), fcntl64);
  94 # else
  95 #  define fcntl fcntl64
  96 # endif
  97 #endif
  98 #if defined(__USE_LARGEFILE64) && !defined(__LP64__)
  99 extern int fcntl64 (int __fd, int __cmd, ...);
 100 # ifdef _LIBC
 101 extern int __fcntl64_nocancel(int, int, long) attribute_hidden;
 102 libc_hidden_proto(fcntl64)
 103 # endif
 104 #endif
 105
 106 /* Open FILE and return a new file descriptor for it, or -1 on error.
 107    OFLAG determines the type of access used.  If O_CREAT is on OFLAG,
 108    the third argument is taken as a `mode_t', the mode of the created file.
 109
 110    This function is a cancellation point and therefore not marked with
 111    __THROW.  */
 112 #ifndef __USE_FILE_OFFSET64
 113 extern int open (const char *__file, int __oflag, ...) __nonnull ((1));
 114 libc_hidden_proto(open)
 115 # ifdef _LIBC
 116 extern int __open2_nocancel(const char *, int) __nonnull ((1)) attribute_hidden;
 117 extern int __open_nocancel(const char *, int, mode_t) __nonnull ((1)) attribute_hidden;
 118 # endif
 119 #else
 120 # ifdef __REDIRECT
 121 extern int __REDIRECT (open, (const char *__file, int __oflag, ...), open64)
 122      __nonnull ((1));
 123 # else
 124 #  define open open64
 125 # endif
 126 #endif
 127 #ifdef __USE_LARGEFILE64
 128 extern int open64 (const char *__file, int __oflag, ...) __nonnull ((1));
 129 libc_hidden_proto(open64)
 130 #endif
 131
 132 #ifdef __USE_ATFILE
 133 /* Similar to `open' but a relative path name is interpreted relative to
 134    the directory for which FD is a descriptor.
 135
 136    NOTE: some other `openat' implementation support additional functionality
 137    through this interface, especially using the O_XATTR flag.  This is not
 138    yet supported here.
 139
 140    This function is a cancellation point and therefore not marked with
 141    __THROW.  */
 142 # ifndef __USE_FILE_OFFSET64
 143 extern int openat (int __fd, const char *__file, int __oflag, ...)
 144      __nonnull ((2));
 145 libc_hidden_proto(openat)
 146 # else
 147 #  ifdef __REDIRECT
 148 extern int __REDIRECT (openat, (int __fd, const char *__file, int __oflag,
 149                                 ...), openat64) __nonnull ((2));
 150 #  else
 151 #   define openat openat64
 152 #  endif
 153 # endif
 154
 155 extern int openat64 (int __fd, const char *__file, int __oflag, ...)
 156      __nonnull ((2));
 157 #endif
 158
 159 /* Create and open FILE, with mode MODE.  This takes an `int' MODE
 160    argument because that is what `mode_t' will be widened to.
 161
 162    This function is a cancellation point and therefore not marked with
 163    __THROW.  */
 164 #ifndef __USE_FILE_OFFSET64
 165 extern int creat (const char *__file, __mode_t __mode) __nonnull ((1));
 166 #else
 167 # ifdef __REDIRECT
 168 extern int __REDIRECT (creat, (const char *__file, __mode_t __mode),
 169                        creat64) __nonnull ((1));
 170 # else
 171 #  define creat creat64
 172 # endif
 173 #endif
 174 #ifdef __USE_LARGEFILE64
 175 extern int creat64 (const char *__file, __mode_t __mode) __nonnull ((1));
 176 #endif
 177
 178 #if !defined F_LOCK && (defined __USE_MISC || (defined __USE_XOPEN_EXTENDED \
 179                                                && !defined __USE_POSIX))
 180 /* NOTE: These declarations also appear in <unistd.h>; be sure to keep both
 181    files consistent.  Some systems have them there and some here, and some
 182    software depends on the macros being defined without including both.  */
 183
 184 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
 185    LEN is always relative to the current file position.
 186    The CMD argument is one of the following.  */
 187
 188 # define F_ULOCK 0      /* Unlock a previously locked region.  */
 189 # define F_LOCK  1      /* Lock a region for exclusive use.  */
 190 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
 191 # define F_TEST  3      /* Test a region for other processes locks.  */
 192
 193 # ifndef __USE_FILE_OFFSET64
 194 extern int lockf (int __fd, int __cmd, __off_t __len);
 195 libc_hidden_proto(lockf)
 196 # else
 197 #  ifdef __REDIRECT
 198 extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len), lockf64);
 199 #  else
 200 #   define lockf lockf64
 201 #  endif
 202 # endif
 203 # ifdef __USE_LARGEFILE64
 204 extern int lockf64 (int __fd, int __cmd, __off64_t __len);
 205 # endif
 206 #endif
 207
 208 #if defined __USE_XOPEN2K && defined __UCLIBC_HAS_ADVANCED_REALTIME__
 209 /* Advice the system about the expected behaviour of the application with
 210    respect to the file associated with FD.  */
 211 # ifndef __USE_FILE_OFFSET64
 212 extern int posix_fadvise (int __fd, __off_t __offset, __off_t __len,
 213                           int __advise) __THROW;
 214 # else
 215 #  ifdef __REDIRECT_NTH
 216 extern int __REDIRECT_NTH (posix_fadvise, (int __fd, __off64_t __offset,
 217                                            __off64_t __len, int __advise),
 218                            posix_fadvise64);
 219 #  else
 220 #   define posix_fadvise posix_fadvise64
 221 #  endif
 222 # endif
 223 # ifdef __USE_LARGEFILE64
 224 extern int posix_fadvise64 (int __fd, __off64_t __offset, __off64_t __len,
 225                             int __advise) __THROW;
 226 # endif
 227
 228 #endif
 229
 230 #if defined __UCLIBC_HAS_ADVANCED_REALTIME__
 231
 232 /* Reserve storage for the data of the file associated with FD.
 233
 234    This function is a possible cancellation point and therefore not
 235    marked with __THROW.  */
 236 # ifndef __USE_FILE_OFFSET64
 237 extern int posix_fallocate (int __fd, __off_t __offset, __off_t __len);
 238 # else
 239 #  ifdef __REDIRECT
 240 extern int __REDIRECT (posix_fallocate, (int __fd, __off64_t __offset,
 241                                          __off64_t __len),
 242                        posix_fallocate64);
 243 #  else
 244 #   define posix_fallocate posix_fallocate64
 245 #  endif
 246 # endif
 247 # ifdef __USE_LARGEFILE64
 248 extern int posix_fallocate64 (int __fd, __off64_t __offset, __off64_t __len);
 249 # endif
 250 #endif
 251
 252 #if (defined __UCLIBC_LINUX_SPECIFIC__ && defined __USE_GNU) || defined _LIBC
 253 /* Reserve storage for the data of a file associated with FD.  This function
 254    is Linux-specific.  For the portable version, use posix_fallocate().
 255    Unlike the latter, fallocate can operate in different modes.  The default
 256    mode = 0 is equivalent to posix_fallocate().
 257
 258    Note: These declarations are used in posix_fallocate.c and
 259    posix_fallocate64.c, so we expose them internally.
 260  */
 261
 262 /* Flags for fallocate's mode.  */
 263 # define FALLOC_FL_KEEP_SIZE            1 /* Don't extend size of file
 264                                              even if offset + len is
 265                                              greater than file size.  */
 266 # define FALLOC_FL_PUNCH_HOLE           2 /* Create a hole in the file.  */
 267
 268 # ifndef __USE_FILE_OFFSET64
 269 extern int fallocate (int __fd, int __mode, __off_t __offset, __off_t __len);
 270 # else
 271 #  ifdef __REDIRECT
 272 extern int __REDIRECT (fallocate, (int __fd, int __mode, __off64_t __offset,
 273                                    __off64_t __len),
 274                        fallocate64);
 275 #  else
 276 #   define fallocate fallocate64
 277 #  endif
 278 # endif
 279 # ifdef __USE_LARGEFILE64
 280 extern int fallocate64 (int __fd, int __mode, __off64_t __offset, __off64_t __len);
 281 # endif
 282 #endif
 283
 284 #if (defined __UCLIBC_LINUX_SPECIFIC__ && defined __USE_GNU)
 285 struct file_handle {
 286         unsigned handle_bytes;
 287         int handle_type;
 288         unsigned char f_handle[];
 289 };
 290
 291 #define MAX_HANDLE_SZ  128
 292
 293 int name_to_handle_at(int dirfd, const char *pathname,
 294         struct file_handle *handle, int *mount_id, int flags);
 295 int open_by_handle_at(int mount_fd, struct file_handle *handle, int flags);
 296 #endif
 297
 298 __END_DECLS
 299
 300 #endif /* fcntl.h  */